Don't use DE, I recommend this because of the Dr's I've heard speak about bio-accumulation and the blood brain barrier, basically part of DE is aluminum, the cananbis will absorb some of this, when you inhale it, you will start bio-accmulating it, once it's in your blood stream it can go straight into your brain and is linked to autism. This is why I've tried to avoid it, my research says you should go for potassium silicate, your plants love the silica and they can always use a little extra P especially in flowering, though you want to use something else, as you'd just be wasting silica at that point. They make sodium silicate but who wants to raise their salts with a one sided benefit.